Relay impulse counter



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T. A. HENDRICKSON RELAY IMPULSE COUNTER Filed Dec. 30. 1957 Rad,

March 29, 1960 A-PULSE ENTRY R5867 MIVENTOR W ,2. ThomAHezzairzbkson BY TTORNEY United States Patent RELAY IMPULSE COUNTER Thomas A. Hendrickson, Poughkeepsie, N.Y., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Application December 30, 1957, Serial No. 705,879

1 Claim. (Cl. 235-92) This invention relates to relay circuits and particularly to an improved electrical impulse counter.

An object of the invention is to provide a novel and 7 simple modular construction whereby the counter may be scheduled to emit output impulses after the counting of a predeterminable number of events.

Another object is to provide a counter which will emit impulses representing various counts, which impulses will be easily available at tap-in points or output plugs for connection to other circuits.

Prior types of impulse counters were subject to disadvantages, such as the possibility of an extra count when the input pulse was extended, or were complicated by necessary cross connections to plural relay coils and points, which tended to destroy the modular nature of the device. It is, accordingly, a further object of the invention to overcome these disadvantages.

Other objects of the invention will be pointed out in the following description and claim and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In the drawings:

Fig. 1 is a schematic electrical diagram of one embodiment of the invention.

Fig. 2 is a timing diagram showing the relationship between the two pulses required by the embodiment as shown in Fig. 1.

Fig. 3 is a schematic electrical diagram of a second embodiment of the invention, in which only one type of pulse is required.

Preferred embodiments of a counter, in accordance with the invention, as shown in the drawings, comprise a continuous number of series of latch-type relays, an example of which is described in Patent No. 2,510,604 issued June 6, 1950, to Wesley Pfaff et a1. Such a relay is distinguished by a latch which mechanically locks the pick armature in the operated position even after the electrical current stops. The relay drops only when the latch is attracted by the trip coil, moving the latch away from the pick armature, which returns to normal under spring tension.

The counter operates by starting the count with all the counting relays in latched condition, then dropping out one latched-up relay for each count, which prepares circuits for counting the next impulse. A counter for counting to 8, Le, which will block 7 impulses but pass the eighth, requires 7 counting relays.

In the embodiment as shown in Fig. l, the events to be counted by the impulse counter are represented by electrical impulses which are supplied to the entry terminal 1 from a suitable source of A pulses (not shown) and are of correct voltage and polarity to operate relays, and timed as shown in Fig. 2. Various methods of converting events into electrical impulses and of amplifying, polarizing, and timing these impulses, are well known in the art.

At the start of operation, counting relays R1 through R4 are assumed to be in the unlatched or normal condition. The movable blades of transfer points R1aR4a are in the normal position, making contact with their normally closed stationary points. Before counting begins it is necessary to switch all of the counting relays to the latched condition, which is the zero condition of the counter.

For this purpose an A pulse is supplied to the entry terminal 1. This pulse passes through the series of normally closed points Rla-R4a, terminal 5, plug wire 7, reset terminal 6, pick coil P of reset relay R5, to line 8, energizing the reset relay R5. Normally open relay point R5e closes, preparing a circuit through which a B pulse, from a suitable source (not shown) passes from line 9 before the A pulse terminates (see Fig. 2), energizing the hold coil H of relay R5. When relay R5 is energized by the A pulse, as above described, the movable blades of relay transfer points RSa-RSd transfer to their normally open stationary contacts preparing circuits through which the B pulse passes in parallel to the pick coils P of relays R1R4 and line 8, energizing said coils and switching said relays to the latched or zero condition. When the B pulse terminates, the reset relay R5 drops, allowing the movable blades of transfer relay points R5aR5d to return to their normally closed contacts, preparing parallel circuits to both the pick and trip coils of each counting relay R1--R4. The counter is ready to start counting A pulses supplied to entry terminal 1, the movable blades of relay points R1a--R4a being all transferred to the normally open stationary contacts and held by the mechanical latches.

The first A pulse of electricity, representing the first event to be counted, enters at entry terminal 1, passes through the transferred point Rla of the mechanically latched counting relay R1, thence in parallel through the trip coil A relay R1 to line 8, and through the normally closed point RSa and the pick coil P of relay R1 to line 8, energizing both coils of said relay as a group. Counting relays R1-R4 are designed and adjusted so that when both coils are energized the relay will transfer, or stay transferred, until the end of the pulse; when the pulse ends, because of the particular design and adjustment, the relay drops. Each relay drops because the latch pick armature has dropped past the latching point before the latch trip armature can drop into the latching position. Counting relay R1 indicates a count of 1 by being in the down state. There can be no spurious 2 count because the normally closed lower point Rla of counting relay R1 cannot close until the end of the first entry pulse. The second entry pulse enters the entry terminal 1, passes through the normally closed point Rla of relay R1, which has been dropped by the first pulse, to the output terminal 2 and through the transferred point R2a of the mechanically latched counting relay R2 to energize the latch trip coil T of counting relay R2. R2 does not drop until the end of the second entry pulse because of the parallel circuit from R2 trip coil through the normally closed point R5b of the reset relay R5 which energizes the pick coil P of counting relay R2. There will be no spurious 3 count because the normally closed point R211 of counting relay R2 cannot close until the termination of the second impulse. The third impulse enters at entry terminal 1, passes through normally closed point Rla to the output terminal 3 and normally closed point R2a, through the transferred point R3a of counting relay R3 to energize the trip coil T of counting relay R3. The parallel circuit through reset relay R5 normally closed point RSc to energize the pick coil P of relay 3 prevents a spurious 4 count. In like manner, the fourth impulse enters at entry terminal 1, passes through normally closed points R1a-R2a-R3a to the output hub 4 the Output terminal 5.

The terminal for the particular output 'desir'ed ma be trated and in its operation may be made by those skilled in "the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claim.

What is claimed is: In an impulse counting system, a series of latch-type electromagnetic relays representing respective values of connected to other circuits for any desired use, and may also be connected to the reset terminal to reset the counter to its latched or zero position for a repetitive counting operation. Any output terminal may be used as an entry if variations in the counting operation are desired. l

The output terminals in the counter will erriit each A pulse applied after the appropriate count "and before reset. For instance, terminal 3 will not emit A 'pulse's 1 and 2, but will emit A pulses 3, 4 and 5, unless a reset pulse is transmitted. p

In the embodiment of Fig. 3, reset on the fourth pulse is accomplished by the entry vpulse, which is connected by wire 7 to the reset terminal 6 from exit terminal 4, and which picks the reset relay R5. R holds through its R51 point to the entry terminal 1. Points R5 RSg, R5h transfer, opening the paths by which the trip coils of relays R'1- -R3 were connected in parallel in groups with their related pick coils. The latches drop. Normally open points R5 RSg, R'5h close to establish a connection between the entry terminal '1 and the pick coils of relays R1, R2, and R3, which latch mechanically as their armatures move to the picked condition. The counter is reset to the latched or zero condition.

Reset may be accomplished by any other means, such as a mechanical cam, without departing from the spirit of the invention. v

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of thedeviceillusa continuous number series, each comprising a movable armature, a pick coil to move said armature to an operated position, a latch to hold said armature in the operated position, and a trip coil to release said latch, each of said relays having the characteristic of returning to the normal position when its pick coil and its trip coil, after being energized, are 'de-energi'z'ed concurrently; an entry-pulse terminal; circuit means for selectively connecting the pick coil and the trip coil of each of said relays as a group to said terminal; said circuit means including switching means controlled by each relay to connect said entry-pulse terminal to the group of coils of said relay when said relay is latched; said switching "means being adapted, when the related relay is latched, to interrupt the connection between said terminal and the coil groups of all relays 'of higher value, and being adapted, wen the related relay is unlatched, to establish a circuit path from said terminal to the coil group of the relay of next higher value; means for resetting all of "said relays to the latched condition; and an output terminal connected to said entry-pulse terminal by the unlatched relay of highest value. a 

